1. Field of the Invention
The present invention relates to bag-in-bottle packages which include a resilient squeeze bottle and and inner receptacles incorporating a flexible bag for housing a viscous product, and more particularly, to such inner receptacles which include a flexible product bag which inverts upon emptying.
2. Description of the Prior Art
A wide variety of packages are known which include an outer squeeze bottle and an inner flexible product bag. Generally, the outer squeeze bottle includes a resilient side wall portion which when compressed, forces product from the bag through a dispensing passage. The dispensing passage generally includes a valve which prevents air from entering the product bag when the outer squeeze bottle is released. The squeeze bottle also generally includes a second valve which enables air to re-enter the outer squeeze bottle into the space located between the inner flexible product bag and outer squeeze bottle. Consequently, the inner product bag collapses as product is dispensed. One problem with such packages is that the inner flexible bag has a tendency to collapse prematurely; trapping product within the inner flexible bag so it cannot be dispensed.
One method to ensure that product is not trapped inside the inner flexible bag is to provide a mechanism for causing the bag to invert about its midpoint. U.S. Pat. No. 2,608,320, issued to Harrison on Aug. 26, 1952, discloses such a package which provides for bag inversion. This package requires that a thinner, flexible, lower bag portion be sealed to an upper, thicker, rigid, bag portion around the entire curved circumferential surface of the bag in an air tight manner. However, complete sealing along such a curved surface is difficult to accomplish; particularly when utilizing heat sealing. In addition, the rigid top portion is not resilient such that it is squeezable. Thus, the user is only able to squeeze the bottom portion of the package.
Commonly assigned U.S. Pat. No. 4,842,165 which issued on Jun. 27, 1989 to Van Coney discloses a package which includes an inner receptacle having a flexible product bag. The bag of the inner receptacle is secured to the interior surface of the side wall of the outer squeeze bottle about its midpoint to provide bag inversion. In the illustrated embodiments of the Van Coney invention the inner receptacle is secured by attachment of its outermost surface to the innermost surface of the squeeze bottle; preferably by means of adhesive or by heat sealing.